The Blue Hen Stakes is an American Thoroughbred horse race for two-year-old fillies held annually in early October at Delaware Park Racetrack in Stanton, Delaware.

A non-graded stakes event raced on dirt, since 2004 it has been contested at a distance of one and one-sixteenth miles (8.5 furlongs).

The Blue Hen is named for the horse breeding term "Blue Hen," meaning a mare who has proved herself exceptional in producing high quality foals, almost regardless of which stallion might be the sire.

[1] These sons and daughters would also affect the breed.

An example of the highest sort of Blue Hen mare would be La Troienne.